ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
resembles gelatin in consistency. Substances like glucose can be added 
if desired. 
A large variety of bacteria have been found to grow on tbis medium 
with great readiness. 
Noil-albuminous Cultivation Media for Vibrios.*-- Dr. A. Maassen 
recommends that vibrios be cultivated in a normal medium, one made up 
according to definite rules. The composition of the normal solution is 
as follows : — 7 grm. of malic acid are dissolved in about 100 ccm. of 
H 2 0 and neutralized with pure KHO. The solution is diluted with dis- 
tilled water up to 1 litre, and then there are added 10 grm. finely 
powdered asparagin, 0*4 grm. magnesium sulphate, 2*0 grm. biphos- 
phate of soda, and 2 * 5 grm. of pure crystalline soda. When the whole 
of these ingredients are properly dissolved 0*01 grm. of dry calcium 
chloride is added. 
In this solution the malic acid can be replaced by equivalent 
quantities of other organic acids suitable as nutrient material, the potash 
by soda, the asparagin by an ammonia salt of an organic or inorganic 
acid, by various other nitrogenous organic substances, amides, amido- 
acids, urea, kreatin ; the soda may be diminished and the quantity of 
water increased. Moreover, to this normal solution in its simple or 
varied form other assimilable carbohydrate compounds may be added, e. g. 
mannit, or other kinds of sugar, ethylen-glycol, glycerin, or dextrin. 
In such nutrient solutions with variable amounts of cane-sugar, milk- 
sugar, maltose, galactose, grape-sugar, or dextrin, scum-forming vibrios 
develope luxuriantly, forming a thick membranous scum in 24 hours. 
The scum in a few days becomes puckered, and the fluid, at first as clear 
as water, turns yellow or yellowish-brown, the reaction altering just as 
it does in sugar-serum-bouillon. When pepton is added the production 
of indol occurs after the recurrence of the alkaline reaction. In non- 
albuminous solutions luminous vibrios develope luminosity in 18 hours. 
The Bujwid Reaction and Bouillon Cultivations.! — Dr. Inghilleri 
finds that some micro-organisms are capable of living in bouillon in 
which cholera bacilli have been previously cultivated and which gives 
the nitroso-indol reaction very clearly. Their behaviour is, however, 
not the same, since they act differently on the inorganic combinations of 
nitrogen ; for example, while some develope without modifying the 
Bujwid reaction, others destroy it. This is specially frequent with the 
bacilli of the alimentary canal, e. g. B. coli commune , which reduces 
nitrates to ammonia and other combinations of nitrogen. The indol is, 
however, undecomposed, and in the B. coli cultures it actually increases 
so that it is always possible to demonstrate its presence by means of 
Kitasato’s reaction. 
If B. coli or B. typhosus be cultivated along with cholera bacillus 
on meat-pepton solution, then the fluid shows, instead of Bujwid’s 
reaction, only that of Kitasato. In this way an important diagnostic 
criterion of cholera is lost, and this should be borne in mind in reference 
to bacteriological examination of suspected cholera stools, for not with - 
* Arb. a. d. Kaiserl. Gesundheitsamte, ix. (1894) pp. 401-4. See Centralbl. f. 
Bakteriol. u. Parasitenk., xv. (1894) pp. 922-3. 
f Centralbl. f. Bakteriol. u. Parasitenk., xv. (1894) p. G88-9. 
